Stuart Brown, 28, from Bangor, County Down, in Northern Ireland, said the catch was “a surprise to everybody”.

The remarkable creature was found near Blackhead Lighthouse after it was brought up in a pot off the northern shore of the lough.

The lobster was however too small to keep and so was forced to release it back into the water – once he’d taken his pictures.

He said: “It’s still out in the lough somewhere, swimming about as happy as can be. Hopefully, if someone else does catch it, they’ll return it as well.”

His boat was in deep water at the time of the catch – around 15-18 metres.

Describing the find, he said: “I slid the pot down to the crewman who lifted it out and he made a comment: ‘That’s very blue’.

“I looked at him and said: ‘Yeah, no problem.’ But then I did look at it again and said: ‘That’s too blue.’”

Already a veteran fisherman having started out when he was 11, he added: “You would get lobsters out there that don’t look normal, they’d be a bit browner or redder, just something different with them, but nothing that extreme.

“I looked up Google to see how rare it was, and it was one-in-two million chance of catching it.”

The County Down seafood whole business shareholder said it was now one “weird and wonderful things” found in the ocean he could tick off his list.

Genetic differences can make some lobsters come out in a different colour to the more commonly found brown or red variety.

The difference means that certain proteins are made at different rates from others.

Scientists reckon that the chance of catching a blue lobster is about one in two million, meaning it really was Stuart’s lucky day.